Neck pain is a common musculoskeletal complaint with a reported annual prevalence ranging from 30% to 50%. Neck pain constitutes a major cause of disability in the western world with significant consequences for the injured individuals and for society at large. While disability due to neck pain entails various impairments such as reduced repositioning ability, diminished muscle activity and decreased isometric strength, limitation in cervical motion is the impairment most frequently clinically observed.
Cervical Range of Motion (CROM) assessment is frequently used to quantify the level of impairment associated with neck pain, to discriminate between asymptomatic persons and those with persistent neck pain related to different pathologies and to assess effectiveness of therapeutic interventions.
CROM assessment as a diagnostic tool is challenging due to previous studies that showed low specificity and sensitivity. A variety of means including eye-balling, radiographs, goniometers and inclinometers, as well as more advanced technologies such as ultrasonic, optic and electromagnetic motion tracking devices can be used.
Goniometers and inclinometers are used extensively for clinical purposes, but they are limited to measuring primarily two-dimensional motions under static conditions. Motion tracking devices may be used to measure three-dimensional motions under dynamic conditions, but their use is limited to research due to their cost and technical complexity.
CROM assessment is typically carried out by instructing subjects to move their head as far as possible in each of the tested planes of motion. However, the reliability of these assessment methods is questionable, as elicited conscious movements do not necessarily replicate typical functional movements which occur spontaneously in response to multiple natural stimuli. In daily life individuals turn their heads to maximal range unconsciously in response to hearing a sudden noise, or when attempting to perform actions such as driving a car in reverse or locating an attractive scent.
U.S. Pat. No. 6,613,003 titled “Test apparatus for determining a cervical acceleration injury” to “Hollandse Exploitatie MIJ BV” describes a system to evaluate vestibular deficits, claimed to be associated with whiplash. With this apparatus, normal environment is manipulated and there is no active involvement of the patient—thus no everyday function is assessed. Moreover, it does not measure mobility of the cervical spine or the quality of the motion (in terms of speed or smoothness) and is relevant only to a sub-group of whiplash patients who complain of vestibular problems such as dizziness.
In their paper on manual therapy titled “Sensorimotor disturbances in chronic neck pain—Range of motion, peak velocity, smoothness of movement, and repositioning acuity” Sjolander P et al. describe an evaluation of sensorimotor function in patients with chronic neck pain in comparison to the healthy subjects (Sjolander P, Michaelson P, Jaric S and Djupsjoebacker M, Manual Therapy, Volume 13, Issue 2, Pages 122-131). It is noted that Sjolander P et al. provide an analysis of cervical motions which are elicited by oral commands International Patent Application, publication number WO 2004/043,257 titled “Device for the diagnosis and/or therapy of functional disorders of the cervical spine” to Fraunhofer Ges Forschung et al describes a device used for tracking cervical motion. However these devices do not stimulate user reaction to unexpected targets which is a typical real-life scenario.
International Patent Application, publication number WO 9115148 titled “Non-invasive method of and equipment for determining kinematic movement of the cervical spine” to Fuhr Arlan W also describes equipment targeted towards assessment of cervical motion. The equipment described uses a flat display, thus limiting the angular cervical motion potential of the subject. In addition, the system is not adaptive to the specific subject's ability as displayed during the assessment session.
International Patent Application, publication number WO 02089923 titled “Apparatus for cervical region diagnostics and training” to Physiotech Aps describes a device where patients are requested to place their head inside the apparatus. Replication of a person's spontaneous posture cannot be achieved under such conditions.
U.S. Pat. No. 6,774,885 titled “System for dynamic registration, evaluation, and correction of functional human behavior” to Motek B V describes a system that uses virtual environments for assessment of global body motions and postural changes, and has interesting applications in the field of rehabilitation. This system, however, does not measure the neck and its kinematics. It is a whole body training system, which is targeted mostly towards achieving posture and balance.
The need remains, therefore, for an affordable system and methodology to assess cervical motion while simulating real life scenarios. Moreover, there's a need for similar systems and methods to assess linear and angular functional motion parameters of different body parts in human and non-human subjects.
Embodiments described hereinbelow address this need.